Automatic choke valve



Aug. 3, 1943.- L E. PERRINE 2,325,918

, AUTOMATIC CHOKE VALVE Filed March 31, 1932 valve opens isof greater area than the portion on' brass or some/other non-magnetic material, 'and'.

on which there areprovided two laterally spaced, upstanding ears I9. In thev outer ends of the ears on parts of the engine other than the intake manifolds, and, moreover, if it is so desired, the mechanisms may be so mounted that the thermosensitive elements will be affected by the heat radiated from parts of the engines other than the exhaust manifolds.

yThe thermo-sensitive element 25 is so constructed andarranged that, as its temperature rises,- it tends to rotate the shaft 2 i yin a counterclockwise direction, as viewed in Figure l, and to a open the choke valve i8, that, as its temperature 19, there are provided alined bores through which there extends and in which there is journalled a shaft 2l. To one end of the shaft 2 l, there is fixed a crank arm 22 which is connectedby a link 23 to an operating arm 2i which is fixed to theshaft` l onl which the choke valve I6 is mounted. To the opposite end of the shaft V2i, there is secured theinner end of a b-metallic thermo-sensitive coil spring 25 which is located within and whose outerend is secured to a cupshaped housing 28 which is adjustably secured to the'ba'se I3 by means of a clamping element 21 Y which is carried by the adjacent ear l 9.

The portion'o'f the vshaft 2l intermediate the ears IIS passeslthrough openings formed in ears 28 which are formed onone end of a platform 23 whichnis preferably made of brass or 'some other non-magnetic material `and serves to support and pivotally connect one end of theplatform to the baseflS. To the base'lS at a distance from the ears I9, there-'is secured a stud 3i) which extends through an opening in the adjacent end ofthe platform '29. The portionof thestud 35i-below the platform is surrounded by `a coil spring 3l whichf. urges the upper surface of the platform into contact-With the lower side of a nut 32 which isthreaded on the portion of the stud above the" platform. vTo a lateral extension which is formed on the side of the baselV li` on which the housingr 26 is'locatedV at the endthereof distant from the housing, there is secured one end ofa bi-metallic thermo-sensitive strip 33 throughwhose free end which over-lies the adjacent end of the platform 29 thereextends a set screw 34. The portion ofthe shaft 2l between the ears -28 of theiplatform 29 passes through the intermediate portion Of'anL-Shaped keeper 33whicl1 is preferably made of a ferrous metal and fixed '50 valve I6 is in fully. closed position, as shownf'in to the shaft by a.` set screw 36. When the choke the drawing-the'shorter arm 3T of the-keeper35 extends substantially vertically downwardly between the 'ears I9 and the longer arm 38 thereof extends substantially horizontally and overlies the poles of a vU-shaped.' permanent magnet 39 Whose bightis secured tothe rplatform'Zil between the shaft 2l and the stud 3U by means of ascrew 4U.' i n In the installation illustrated in the drawing,

the mechanism for automatically maintainingithe i which the relative positions of the intake and ex- Y haust vmanifolds differ from that illustrated in theA drawing, it may be found desirable, in order soto locate the thermo-sensitive elements .that they will -be affected.V by the heat radiated from Y the exhaustmanifolds, to mount the mechanisms falls, it tends to rotate the shaft 2l in a clockwise direction and to close the choke valve, and that, when temperature falls below a predeterminedvminimum (e. g. 70 E'. to 89 F), if unresisted, it will maintain the choke valve in fully closed position. From what wasV said in the preceding sentence,'it will be apparent that the thernio-sensitive element 25, when its temperature is below the mentioned predetermined minimum, tends to maintain the choke valve in fullyl closed position, and, when its temperature equals or exceeds Ythe mentioned predetermined minimum, tendstoregulate the position of the choke valve in accordance withlits temperature, and, since the thermo-sensitive element 25 is affected bythe temperature of the exhaust manifold dl, in accordance with, thetemperature of the exhaust manifold*` lVforeoverQitv/*ill be noted that the attraction of themagnet 39 for the arm'38 of the keeper 35 tends to'prevent rotation of the shaft 2| ina counter-clockwise direction, and, therefore, to maintain the choke Avalve in a closed position. v I f When thee-rigine on which the mechanism described andillust'rated in the drawing is installed is not operating, the positions of the parts of the mechanism will depend upon the temperature of the exhaust manifold'of ythe engine. If the engine' is sufficiently heated, the thermo-sensitive element 25 will maintain the choke valve par-y tially -or fullyv open andthe arm 38 of .the keeper 3.5 out of the effective iieidlo'f attraction ofthe magnet'. Under such conditions, the position of the "choke valvefduring starting of the engine Will'be controlled entirely by the thermo-sensitive element andthe volumeY of air l which is flowingfthrough the'conduit Il "I'f; however, iwh'en the engine is not operating,

it.become`ssu1cientiy vcold, the thermo-sensitive element will move'fthe choke valve sufficiently toward c lc-sed'positionto bring the arm 38 of the keeper j35int`o the effective eld of attraction of the magnetSSf which will tend te movey the keeper further in a clockwise direction, and, conse- Qluently",v completely to close `the choke valve. Sinceq the force exerted by a permanent magnet on "an object'varies inversely as the square of the distance" separating the magnet and the object,

the strength ofthe closing force exerted by the magnet l39 will depend upon the position of the magnet-which is urged toward the arm`38 of the keeper by the spring 3l but limited in its movementfby the nut Siler by the set screw 34 which is moved toward the platform 23 when the temperature o-f the thermo-sensitive element 33 rises andaway from the platform when the tempera'- ture thereof falls. Under thel conditions described inthe preceding portion of this paragraph, it is obvious that the position of the choke valve Ilwill depend partly upon the temperature of the thermo-sensitive element. 25 and partly upon the position of the magnet 3S which is affectedby the temperature of the thermo-sensitive element 33. 'If, under these conditions, the engine'is cranked, the tendency of the air flowing throughtheeor-idnit lll to open'the choke V valve.

Will be resisted by the attractive force of tl'iev magnet 3`9Aor the arm lof the keeper 35 and J@he tendency oi .the--thermo-sensitive element .25-

to maintain. the choke -valve in .closed position and; consequently, since under ,the Vconditionsin l which the arm 13B ofthe keeper 35 isv located With' in the .effective eldnof themagnet, the latter dominates thel thermosensitive .element 25 in determining the` posi-tionxof the `choke valve, the

position of the choke valvewill be determined .by

the magnet untilsuch time as the dow of .air through the conduit becomes sueient vtoevercome .the .attraotiveforce of :the magnetior. arm 38 nf the. keeper '35 plus the tendency, if

of the thermo-'sensitive element 25 .to maintain the arm 38 of thekeeper 35 in the eiective eldl eiective field of attraction ofthe magnet is obviousl-y dependent upon the effectivezstrength of the attractive force, which is dependent upon the arm 38 of the keeper 35 and `is at .its'fmaximum when the thermo-sensitive element 33 is so cold that the set screvv 3G is out of Contact -vvith the platform 2G, and decreases rapidly with a rise in temperature .of thethermo-sensitive element 33,

which as its temperature increases, through `the set screw 3e, moves. the platform and the magnet tively cold than when it is relatively Warm.4 When the flow of air through the conduitilV becomes suicient to overcome the attractiveforces of the magnet for the arm 38 ofthe keeper 35 plus the tendency, if any, oi the thermosensitive element engage the arm 3l oi :the keeper distance Which separates the magnet and vthe suchas 33, which renders theeifecti-veist attraction of the meer-iet when'athe-.thicottle Naive has beennpenedzto apredeterminedextent. -JTO this end, fprovide, as sho-Wn in vthe I drawingfa.' shaftz whichis journalled in'v bores which tend't'hroiigh .the ears EB of .the base 28. andhas fern-leden a portion thereof .between the ears.- i `S1 a earn surface .d'3 which is adapted to be brought f into enga-gement with'thearm 3l of thekeeper 35 to open :the :choke valve, to a predetermined,V

extent when the shaft has been rota-tedthrongh a. predetermined. zangle; v siiaftf 4iifiththe .throttle valve so thatfthe:

`position of the s1 'aft willlbe deter-` mined. :bythe .position or the, throttle valve,y there is ed toorieendof they shaft i2 ,anfarm' 4 4 :which fis interconnected, through a link ,ll-5 a beil crank d anda linkjil, to an varm 48 which. is iiXed to the shaft I4 o-n whichrthe .throttle valve'is `mounted. llt .will ,be apparent from a v consideration. .of the structure described in ,the

preceding portion of. this paragraph that `when the throttle-Naive opened to a predeterminedv extent, :the cam surface' @2,3 on Athe shaft 42 will tiallyopen the :choke `valve. y

While, in .connection witlrfcertain engines desirable `to provide a thermosensitive el oi the attractive force or" the .magnet tion with other. engines, it may be desirable to maintain the effective strength or the ,attractive force constantatall temperatures, l, d, in connection -vvithfstill other engines, torqoder; the

25 to maintain the arrn'SS of thekeeper 345 in the effective vheld of attraction Vofthe magnet, they arm will be moved o utof the eective field of atmay` beemployed vin conjunction with the mechanism herein disclosed, if there is provided some mechanism by which the arm `38,0f ther-keeper 3T: will be movedout of the effective eld of attraction of the magnet when the ratio of the rate at which air `fiovvs through the" conduitl l or the pressure within the intake manifold i3 to the attractive force of the magnet for the arm 3 8 of the keeper 35 plusthe tendency, if any, of thev thermosensitive element E5 to maintain the arm 3S ci the keeper 35s in the effective field vof attraction of the magnet exceedsa predetermined value.

To insure that 'the choke valve will be open when the throttle valve is vopen to a predetermined extent, there is preferably provided in conjunction vvitli the mechanism hereinbefore de'- scribed, -means 'byfv-Jhich` the armA 33 ofthe Anhougnr have eifectigve strength of Athe e'ttractlveforce greater atrelativeiy leigh temperatures than at r elativel y lowtemperatures. In the, former case, the mag- 4 net 39 .maybe fixed to the basei. In the lata ter case,- the xspring ,3l may be vdisposed between the nut 32 and the -npper surface of the .platiornr 23 and the therm-ofsensitive element '33 arranged Vsojthat its freenendengages the lower surface of the. ,platform yand it tends;

towardthe' arm `3 8 l of fthegkeeper perature rises.A

35 when itsgieinferred embodiment of my inventiom'it is -to -be 'understood-,that this has been doneQby way of example end not by. way Qf-1imiietierrard.C0e=

seqnently, that thescfpe of my invention is to vbe determined only `by the appended` claims` I claim:

Y l. In'jrnechanism for ,regulating the position of the choke valve of ia carburetona magnetic J body Vassociated-vvith -thechoke valve, and aperf marient n iagnetvvhich is so1 arranged' that thev force er'erted thereby tendsto maintainthe body in .a lposition in vWhich'the .choke valve ,is closed..

2. The invention claimed in claim l, plus a Y thermo- Sensitive element' so arranged that the effective force exerted `by the magnet on "theA magnetic bodyfincreases with a der ease in temk perature. X 3. In an internal combustion engine, a foar.; buretor in .which'there is inc orporatedA a ,choke valve :which-is spk arranged that itsposmon'is affectedby pressure variations` infthe ,induction system' ofthe engine,z an armature vassociated kiilitlfrthe vchoke valve, and a magnetic ,body Vivlfii'chis effective Aiii/'hilfe the engineoperating andis 'soarrang'edthat the force eXertedthereb'y keeperfvvillghe moved out .of the Veil'ective l'eicTif-of;

To" 'interconnect V the.

move tliefmlagnet shoiynla'rd described-a pre- V i which the choke valve is closed. g `ri. In an'internal combustion engine, a .carburetor. in which there is incorporated a choke valve which is so arranged that its position is af.

fected by pressure conditions in the induction system of the engine, a thermostat arranged to regulate the position of the choke valve in. ac-

cordance with the. temperature of the engine,

'a' magnetic body associated with the choke.va1ve,.

of the Valve when the pressure is less than a pre-k y determined value.

5. The invention'claimed in claim 4, plus. a thermo-sensitive element .so arranged that the effective force of the magnet on the body increases with a decrease in temperature. i

Y6'.V In a carburetor, a throttle valve, a chok valve, a magnet which tends to hold the choke.

valve in closed position, and mechanism interconnected with the throttle valve for moving the choke valve toward open position after the throttle valve has .been opened tov ay predetermined extent.

V7. In an internal combustion engine, a carburetor in which there is incorporated a choke A n valve, and an armature and a magnetic member` which is effective while the engine is operating under its own power to affect the positionof the choke valve. Y Y

8. In an internal combustion engine, a carburetor inwhich there is incorporated a lchoke valve, a memberrespo'nsive to an engine operating condition to reguiate the position of' the choke valve, and an armature and a .magnetic member which is eective while the engine is operating under its own power to hold the chok valve in a predetermined position. 'Y 9; In an internal combustion engine, a carburetor in which'thereis incorporated a choke tends to maintain the armature. in aposition iniv hold :the4 choke valve in a predetermined position.. A .x

1 3. Inan internal combustion engine, a carburetor in which there is incorporated a choke valve, and means which iseifective while the engine is operating vunder its gown power and whose 'effectiveness varies with an engine operating condition for releasablyholding the choke valve in afpredetermined position.

14. In an internal combustionengine', a carburetor in which there is incorporated a choke valveya magnetic body 'andan'armature which tends to hold the 'choke valve ina predetermined Y position, and means for changing the Y. relative positions of the magnetic body and the armature without affecting the position of the choke valve.

15. In internal combustion engine carburetor choke valve operating mechanism, a body, a cho-ke valve actuating shaft journalled in the b-0dy,-a magnetic member carried by thev body, an `armature carried by the shaft so that it; may move toward and away from the field of attraction of the magnetic member, and means for moving the magnetic member toward and away from the armature inv 'accordance with temperature variations. l Y

V15. In anlinternal combustion engine, a carburetor in which there is incorporated a choke valve, a member responsive to an engine operating condition to regulate the position ofthe choke valve, a. magnetic body andan armature which is eiective while the engine is voperating under its own power to tend to hold the choke valvev in a predetermined position, and means which renders the 'effectiveness of the magnet and magnetic body dependent on an engine operating condition. Y

17; VIn internal combustion engine chokefvalve loperating mechanism, a body, "a choke valve actuating shaft Yjournalled inthe body, a magnetic member carried by the'body, a thermally actuated element Vto Vregulate the position of the *choke valvejcon'nected to the shaft, an armature 'Fcar ried uby theshaft so that it may 'move toward and away from the field-of attraction of the magnet-icv membeiyandmeansf for moving the mag-' valve, and aV magnet and an armature which is*V effective while the engine is operatingl under its own power and whose effectiveness varies with an engine operating condition to affect the'position of the choke valve. Y y l l l 10. In an internal combustion engine, va carburetor in which there isincorporated a choke valve, and a permanent magnet andan armature,

which tends to hold the choke valve in a predetermined position.

Y11. In internal combustion engine carburetor choke valve operating mechanism, a body, aY choke valve actuating shaft Ijournalled in -the body, a 'magnetic member carried bythe body, a two-armed armature carried by the shaft so that one of its arms may move toward and away and a magnetic member which is effective while v the engineis operating under its own power to netic member towardsand away from the arma ture in aocordancewith temperature variations. 18. Ininte'rnal combustionk enginefcarburetor choke valvefoperating mechanism, `a"body, ja

choke valve actuating shaft journalled inthe body,l a member mounted so that it may rock on the shaft, av magnetic'member mounted on the rst-specified member, an armature carried by the shaft so that it may move toward and away from'the field of attraction of'themagnetic inember,"k and means `for rocking the first-'specified .member on the shaft so'as to move the magnetic body toward and away from the'armature in accordance with temperature variations.

19.'Control mechanism for a carburetor comprising a pressure responsive air inlet valve, and magnetic means constantly opposing opening movementv of the valve with a force:varying` with the position of the Valve.

. 20. Control mechanism for a carburetor for use in automotive vehicles, comprising a pressure responsive airinlet valve, a thermostat influencing the movement ofthe valve, and magnetic meansv constantly opposing opening movement of the vaive during operation of the vehicle with a force varying with the position of the valve.

21. Control mechanism'for a carburetor comprislng a pressure responsive air inlet valve, and a permanent. magnet opposing opening movement of the valve only when the valve'is near its closed position. f

22. In an internal combustion engine, a carburetor in Which there is incorporated a'choke Valve, means for resisting movement of the choke vali/e which includes a permanentlmagnet and an armature of which one is nxed'and the other is movable with respect thereto, Vand means for Varying the resistive eiect of the specified means in accordance Vwith changes in temperature.

23. In an internal combustion engine, a carburetor which includesra choke valve,V and means which is effective While thelengine is operating under Aitsown power and Whose effectiveness varieswith theVV temperature forreleasably holding the choke valve in a predeterminedjposition.

24.. In' an internal combustion engine, acar-fv o buretor which includes a choke valvefand amaga l net and an 'armature which is effective `while the engine is operating underits own power and whose effectiveness varies with the temperature 10 to affect the position of the choke valve.V

v LESTER E. PERRINE. 

